I have been an electrician for over (30) years and more than a dozen times I have had a customer state that one incandescent lamp in a group of recessed cans fails within one or two months while the others last. After replacing the lamp of course. I have thought that it could be a loose neutral that momentarily caused 220v, but that has not been the case. Does anyone have any comments or ideas what may cause this?

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The first thing to check is the wattage limitations of the fixture itself. Installing a 200 watt bulb in a fixture rated for 60 watts not only will cause the 200 watt bulb to burn out too quickly, but it also becomes a fire hazard. This is due to the excessive heat that will build up in the fixture and surrounding area.
If the bulbs installed are of the correct, or lower, wattage required by the fixture, the next step is to make sure you are using quality bulbs. Over a short period of time, this cheap bulbs can allow air to seep into the bulb and burn out the filament. Using a better quality bulb avoids this problem.
If you’ve made sure you’ve got the correct wattage of quality bulbs installed and you still are replacing them too often, it may be due to excessive vibration. Some bulbs are subject to shaking simply due to their location. Fixtures near a door are a prime example. Another source of vibration may be the occupants of the building, such as a childs bedroom, or equipment such as an exercise room. The constant movement of these items shakes the walls, floors & cielings, and that vibration is transferred to the bulb's filament. If the fixture can be outfitted with 'rough-service' bulbs, that would be one option to try. Rough service bulbs may also be called garage-door operator bulbs, appliance bulbs, or ceiling fan bulbs. They are designed with additional support for the filament than a standard bulb. Another option to look at is Compact Fluorescent (CF) bulbs, which have no filament. And with todays' advancing technology, you may want to look into Light-Emitting-Diode (LED) lights as well.
If none of the above suggestions seem to help, there’s one more thing to try.
And it comes as a surprise to many that there actually are right and wrong ways to proverbially, ‘screw in a light bulb'. You may be twisting them into the socket too tightly.
By ‘cranking down’ on a bulb during installation you may be causing the most damage to the bulb and socket. Premature bulb failure is often caused by bulbs that have been installed too tightly into light fixtures.
Look into the base of a light fixture socket and you will see a brass tab. This tab is bent at an angle when the fixtures are new and will spring back and forth if depressed slightly. Now take several new light bulbs and inspect the base of each one. You will quickly notice that the bottom of most light bulbs has a small dot of solder in the center of the base. More importantly the size of this drop of solder is not exactly consistent. It is close in size, but not always the same size or height.
If the brass tab at the base of the socket does not make firm contact with the bottom of the light bulb, two things may happen. If there is a poor connection between the brass tab and the base of the bulb, the connection may heat up, and this heat cause the filament to burn out too soon.
If the connection is extremely poor, a small electrical arc can occur that starts to melt the solder and eventually burn a tiny hole through the bottom of the bulb. This hole breaks the vacuum inside the light bulb. When this happens, the gas inside the bulb is replaced by the air in your house and the bulb filament rapidly burns out.
To prevent this arcing you must be sure the brass tab is always at about a 30 degree angle inside the bottom of the socket. People who twist bulbs in tightly will depress and flatten the tab so it does not spring back when a bulb is replaced.
If you discover the tab is flattened, then you must turn off the power to the lights at the switch. As an additional safety measure, turn off the circuit breaker to the lights. Use a needle-nose pliers and carefully grasp the sides of the brass tab and slowly pull it up so the end of the tab is about one quarter inch off the base of the socket.
When you install a bulb always do so with the power off and the light switch on. Screw the bulb in enough for the thread to hold the bulb in place. Turn on the power, and continue turning the bulb. As soon as the bulb comes on, turn the bulb one-eighth of a turn. If you screw the bulb in too tightly, you will once again flatten the brass tab.

Incandescent lamps are typically manufactured with an evacuated internal atmosphere or an inert gas atmosphere. In situations where a leak develops in the lamp vacuum or the internal components of the lamp become contaminated during or after the manufacture of a lamp, the internal atmosphere within the lamp will become contaminated. The presence of oxygen around the hot filament of an electrical lamp results in a reaction between the oxygen and the tungsten of the lamp. As a result, oxidation forms on the lamp filament and collects on the inside of the glass bulb. This condition of oxidation within the internal atmosphere of a bulb is commonly referred to as lamp "white out" because of a white film which collects within the lamp. In some instances, such a violation of the internal atmosphere of the lamp may immediately render the lamp inoperative. More commonly, the lamp initially appears fully operative. However, the lamp has a significantly shorter life span compared to a "good bulb". In many instances, a lamp with a contaminated internal atmosphere can remain operative for thirty (30) seconds or more before the filament breaks, thereby rendering the lamp inoperative. When a lamp whites out, the internal resistance of the lamp increases, while the current through the bulb correspondingly decreases.

HAHA you got me worried a bit sparky. All I read was dark suckers, I didn't even click the link when I read your response

I second that one, I was getting concerned about him.

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fellow sparky . .we have all had that very same scenario . .asnd sometimes with squat success . . .graph recording meters . . .different bulbs...change the fixture .
check wiring . . .on and on and eventually you fix it . . .but it never seems to be a single concrete thing . . heat voltage..arcs..spikes...crappy sockets . .you'll beat it somehow

Finally, we must prove that dark is faster than light. If you were to stand
in an illuminated room in front of a closed, dark closet, then slowly open
the closet door, you would see the light slowly enter the closet, but since
the dark is so fast, you would not be able to see the dark leave the
closet.